Plants for working plates for electronic circuits, for example silicon based or alumina based wafers, in particular for photovoltaic cells or for green-tape type circuits, are known, which comprise at least an alignment device to align the plates that upon exiting the work unit of the plant are incorrectly positioned on the conveyor belt able to move the plates between the various work units of the plant. Here and hereafter, by alignment we mean the positioning of the plate in a symmetrical position with respect to a median axis of the conveyor belt, directed along its direction of feed, so that a median axis of the plate coincides with the median axis of the conveyor belt.
Such known devices comprise gripping members, disposed perpendicularly to the plane of feed determined by the conveyor belt, and parallel to the direction of feed of the latter, able to correct the possible incorrect positioning of the plate, in order to align it so that it may be sent to the next work unit of the plant correctly.
One disadvantage of these known devices is that the gripping members can damage the plate to be aligned, in particular along its edge, which leads to the production of defective pieces. Furthermore, the gripping members can completely break the plate and this causes a complete stoppage of the production cycle in order to remove the broken piece, with the consequent economic problems that derive therefrom.
A further disadvantage of known devices is that the gripping members must be calibrated, or replaced, according to the sizes of the plate to be worked. Therefore, between two working phases of different sized plates, elaborate methods of calibration, or replacement, of the gripping members are required, which considerably delays the production cycle and causes substantial economic losses.
Purpose of the present invention is to achieve an alignment device to align a plate, which does not damage or accidentally break the plate, and which also aligns plates of all sizes without having to be replaced or undergo calibration steps.
The Applicant has devised, tested and embodied the present invention to overcome the shortcomings of the state of the art and to obtain these and other purposes and advantages.